AGROMETEOROLOGICAL
DATA AND FOOD SECURITY
Prof. N.J. Bello
College of Environmental Resources Management
University of Agriculture, Abeokuta
AGROMETEOROLOGICAL DATA AND FOOD SECURITY
Introduction
The four major components of food security are:
Food availability,
Food access,
Food utilization and
Stability of food production system
The four components are affected by climate but food
availability and stability of food production system are
most intimately associated with climate variability and its
changes. Since the 1972 Sahelian drought the falling
trends of food production in this country seem to have
persisted.
Some Few Endangered/Lost crops in Nigeria
Tree Food Crops
Bread Fruit & yield of other fruit trees such as Mango,
Cherry (agbalumo) irvingia, citrus, guava etc have fallen
drastically. Also Fruit number/tree & fruit sizes as well as
their juice content have reduced
Food Crops
Millet, Wheat, Acha, Irish Potato, Cocoyam, Bread
Fruit, Coffee and some yam varieties
Some Few Endangered/Lost crops in Nigeria (Contd.)
Vegetables
Some varieties of vegetables:(Ebolo, Odu,Worowo
Yanrin, Ajefowo Elegede,Isapa & many mushrooms like
Olu, wuruku, Oran, ogogo, takele, tipitipa, agbe abaarun,
eti okete to mention a few
Seeds and Nuts
Bambara nut, Shear nuts, Beni-seeds,Palm
Kernel,G/nuts,Wallnut
Climatic Threats to food security
Anomaly in the variability and change in meteorological
elements (Rainfall, Radiation intensity Temperature,
evaporation, wind) have increased
As a result the incidence of hazards such as drought,
heat waves, floods and abnormal dry spells during the
growing season have become higher
Consequently the soil, livestock and other food
production factors at local and regional scales appear
most vulnerable.
Order of presentation
Agrometeorological Focus of Food Security
The agrometeorological data required for crop growth and yield
Specific Roles of Climatic Elements in Agriculture
Measurement of agrometeorological data
Processing and analysis of agrometeorological data for crop yield
prediction and assessment
Recommendations to strengthen agrometeorological services for
food security
Agrometeorological Focus of Food Security
Understanding of the complex interactions between the atmospheric
environment (Climate),crops and livestock
Prediction and control of the climatic attributes for better agricultural
production and operational Management in crops, livestock and
forestry.
Forecasts of climatic hazards or weather hazards to agricultural
production and the control or protection of crops against such
hazards like floods, drought, wind, heat wave etc
Agrometeorological Focus of Food Security (contd.)
Determine accurate schedule of farm operations such as
time of land preparation, planting, fertilizer application,
amount of irrigation water to ensure optimal crop yield
and advice on time of harvesting of crops.
Understanding, the climatic condition favouring the
breeding and infestation. of plant and animal pathogens
and pests and their prediction, control and management
The appraisal of the climatic characteristics of an area
for the introduction of a specific crop or domestic animal
or a group of plants and animals.
Agrometeorological Focus of Food Security (contd.)
Climatic Classification of different agroecological areas for
agricultural land use planning and particularly the selection of
appropriate crops, agricultural systems and animal husbandry
suitable for a given location
Micro-climatic modification to improve crop yield through the use of
wind shelter mulches, and radiation shield practices.
Use climatic parameters accurately for the storage of harvested
crops in man-modified micro-environments to prevent post harvest
losses due to pests and diseases.
Carry out agrometeorological observations, obtain data and perform
routine data processing
The Agrometeorological Data required for crop growth and yield
The Moisture agrometeorological data are:
Precipitation (Rainfall), )
Evaporation
Evapotranspiration (Potential and Actual)
Soil moisture at different depths depending on
experimental crops
Information on dew and plant leaf wetness
Air humidity ( Absolute and Relative humidity
The Agrometeorological Data required for crop growth and yield (contd.)
The Thermal agrometeorological data are:
Air temperature
Soil temperature at different depths (5, 10, 15, 20, 25
and 30 cm)
Ground and grass minimum temperature
Duration of sunshine/photoperiod
Solar radiation
The Agrometeorological Data required for crop growth and yield (contd.)
Aerodynamic agrometeorological data are:
Wind speed at a height of 2metres
Wind direction
Air pressure
Specific Roles of Climatic Elements in Agriculture
The climatic elements and roles played in agriculture
1.
Precipitation (rain)
Determines the beginning and end of the growing season
Determines condition of soil moisture during the growing season
Has influence on the length of the growing season
Determines time of planting of annual food crops e.g Maize
Critical during the different phenologigal stages of crops.
critical to availability of pasture for animal grazing/organic feeds
critical to seed germination and establishment of seedlings
influences the soil moisture condition of the plant environment
Specific Roles of Climatic Elements in Agriculture (contd.)
2. Air temperature
Conditions the level of the physico-chemical reactions of the plants and
therefore their biological activities
Influences rate of development of plants and thus the length of its
vegetative cycle
It conditions evaporative phenomena
It has a direct influence on the soil temperature near the surface and
therefore conditions the rate of decomposition of organic matter
Determines germination of crops and physiological changes after
germination
Important to organic matter decomposition in the plant environment
Determines the physiologic comfort of animals for best performance
Could influence the infestation of plant and animal diseases
Could contribute to the spread of fire disaster in the plant
environment
Specific Roles of Climatic Elements in Agriculture (contd.)
3. Soil temperature
Influences ramification of plant roots
Has significant impact on the activities of soil organic
matter
Conditions soil thermal balance
Specific Roles of Climatic Elements in Agriculture (contd.)
4.Ground temperature
Influences the physiological adaptation of plants and
animals
Modifies the thermal characteristics of the terrestrial
ecosystem Has influence on the natural habitat of
animals and the micro-organisms in the soil organic layer
Specific Roles of Climatic Elements in Agriculture (contd.)
5. Air humidity
Encourages breeding and infestation of certain plant and animal
pests and diseases
Could significantly reduce the quantity and quality of crop yield
It conditions the inner water balances of plants by restricting the
transpiration exchanges
It tends to reduce the diurnal ranges of temperature and thereby
affecting the radiation balance
Specific Roles of Climatic Elements in Agriculture (contd.)
6. Evaporation and Evapotranspiration
Influences water availability for growth processes of
plant and animals in their various habitats
Determines the consumptive water use or moisture
requirements of plants and animals
Critical to plant’s biological formation and net
photosynthesis
Could dry out the top soil and lead to crop failure
Specific Roles of Climatic Elements in Agriculture (contd.)
7. Solar and Terrestrial radiation
Solar Radiation is crucial to Photosynthesis and
biological or biomass production in plants ( radiation
within the spectral range of 0.4-0.74µ ir referred to as
Photosynthetic Active Radiation; PAR)
Has significant influence on ground and soil
temperatures
The pattern of Solar and Terrestrial radiation influences
the air temperature, evaporation and energy balance in
the plant environment
Specific Roles of Climatic Elements in Agriculture (contd.)
8. Duration of sunshine or/Photoperiod
Critical to flowering and fruit formation
Has effect on diurnal radiation balance
Influences evaporation
Specific Roles of Climatic Elements in Agriculture (contd.)
9. Wind speed
Influences evaporation and diffusion of carbon dioxide
Causes mechanical damage to plants
A transporting agent for sand particles which may harm
the vegetal surfaces of crop plant which may harm the
vegetal surfaces of crop plant
Specific Roles of Climatic Elements in Agriculture (contd.)
10. Soil moisture
Important to seed germination and helps plants to
maintain its natural turgidity
11. Dew
. Delays rise in leaf temperature
Encourages the breeding of plant pathogens
Agroclimatic elements and their measurements
Precipitation (rain)
Rainguage (ordinary, automatic),
memory store rainguage with data logger
Air temperature
Minimum and maximum thermometer
Thermograph/thermo-hydrograph , Temperature sensor
Soil temperature
Soil thermometer, Soil temperature sensor
Air humidity
Wet and dry bulb hydrometer
thermo hydrograph, Humidity sensor
Agroclimatic elements and their measurements (contd.)
Air pressure
Barometer (simple, aneroid) Barograph
Wind speed
A three cup anemometer
Wind direction
Wind vane
Duration of sunshine
Campbell stroke sunshine recorder
Evaporation
Class A pan , lysymeter, evaporation sensor
Agroclimatic elements and their measurements (contd.)
Solar radiation
Pyrheliometer ( radiation intensity)
Pyramometer (shortwave radiation)
Pyradiometer (infrared and short-wave solar radiation)
Net radiometer (net radiation)
Pygeometer: ( infrared or long-wave radiation)
Albedometer ( albedo of a surface)
Ground temperature
Grass minimum temperature/sensor
Soil moisture
Soil moisture probe/ sensor
Some important considerations for sitting an agrometeorological station
The area must be well drained
It must not be on a sloppy ground
Must be far from any obstruction e.g. building, trees e.t.c.
Avoid changes in the location of a weather station or changes in the natural
and or man-made environment around it
In an area of uniform terrain weather stations should be randomly
distributed over space
In an area of about 100 square km about 5 weather/ rainfall stations
could serve satisfactorily
Processing and analysis of agrometeorological data for food security
Rainfall (From daily rainfall records determine the following)
Dry days and Dry Spells and their probabilities
Wet days and wet spells and their probabilities
Onset, Cessation and duration of the rainy season
Persistence on transition of the mean dates of the onset
of the rain.
Probabilities of persistence of transition of categories of
wet and dry days as well as the early normal and late
onset of the rain
Rainfall variability and seasonality
Replicability of seasonal rainfall
Processing and analysis of agrometeorological data for food security
(contd.)
Rainfall; crop water requirement satisfaction index
Actual water availability during crop’s phenological stages
Actual water availability- consumptive water use ratio
Decadal rainfall
Decadal water requirement satisfaction index
Heptadal rainfall
Heptadal water requirement satisfaction index
Pentad rainfall
Pentad water requirement satisfaction index
Processing and analysis of agrometeorological data for food security
(contd.)
Temperature
Cardinal temperature of crops and physiological
temperatures
Soil moisture
Actual water capacity of the soil
Evaporation and evapotranspiration
Reference crop evapotranspiration (lysimeter studies)
Petad, heptadal and decadal crop consumptive water
use
Recommendations to strengthen agrometeorological services for
food security
Adequate number of agrometeorological stations
(conventional and automatic) should be set up in each
agro ecological region to obtain relevant climatic data
Attempt a regular classification of climate to define
macroclimatic zones with specific characteristics that can
be exploited for food security
Provides useful information for soil and water
conservation
Device means of reducing the risk from unusual or
extreme meteorological events
Recommendations to strengthen agrometeorological services for food
security (contd.)
Produce agro-climatological maps and review from time to time the
condition of production potentials of various crop at different
locations
Produce pentads, Dekads, and Heptadal agrometeorological
bulletins to be able to effectively track down the pattern of climatic
variation and change
Use agrometeorological models to select more suitable crops for the
climate and provide climatic advice that farmers can use for
improving their agricultural production
Use appropriate crop-water balance model to optimize climate
fertility interactions on yield.
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